Isgl3d获取视屏点击位置

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

// Test for touches if no 3D object has been touched

UITouch* touch = [touches anyObject];

NSUInteger numTaps = [touch tapCount];

CGPoint tapPoint = [touch locationInView:touch.view];

NSLog(@"%f %f\n", tapPoint.x, tapPoint.y);
}